History FaceHeelTurn / WesternAnimation

* Harvey Dent going from the respected attorney he was to the dangerous criminal Two Face in ''WesternAnimation/BatmanTheAnimatedSeries'' is done as a serious TearJerker. He had already been an established and likable character beforehand who suffered from anger issues until a disfiguring injury pushed him over the edge and made his [[SplitPersonality psychotic alternate personality]] become dominant, and Batman has never ''once'' stopped regretting being unable to save him ''or'' given up on swaying him back to being a good guy.
* Mirroring Harvey is Detective Ethan Bennet in ''WesternAnimation/TheBatman'' who, due to an abusively BadBoss, being "[[MindRape clowned with]]" by The Joker, and a harsh dose of mutagenic gas, becomes the amorphous shapeshifter Clayface. Unlike Harvey he struggles much more with morality, initially only being out for revenge, trying to live a normal life, and even attempting to use his powers for good, before his degrading sanity makes him decide BeingGoodSucks and he'd rather be a criminal. [[spoiler:He eventually ''does'' get better for good, helping Batman take out the much more dangerous Clayface II and being cured in the process.]]

* ''WesternAnimation/GreenLanternTheAnimatedSeries'': This happens to Aya after she shuts down her emotions and takes over the Anti-Monitor's body, becoming a KnightTemplar bent on eliminating all organic life to the pointat she goes back in time to rewrite the creation of the universe. [[spoiler:She comes to her senses when she accidentally nearly kills Razer.]]
* In ''WesternAnimation/IronManArmoredAdventures'', Gene Khan does this in spectacular fashion during the second half of the season finale. Given that the writers had spent the entire first season making this character friends with the hero, humanizing him and integrating him into the TrueCompanions, this is actually fairly stunning, especially given that this show loves sympathetic villains being redeemed the way it does.
** One could argue that Gene made his original turn at the start of the series, when he threw down his stepfather and took the role of Mandarin for himself. Outing himself to his friends after they out themselves as Team Iron Man just sealed the deal.
** Whitney Stane has often straddled the line between good and evil ever since she's donned the identity of "Madame Masque", going from UnluckyChildhoodFriend towards Tony to StalkerWithACrush to him, with murderous tendencies towards her father, to redemption, to a brief AntiHero stint as Madame Masque, and LaserGuidedAmnesia that led her to be DemotedToExtra. [[spoiler:Her heel turn is permanently established in "Iron Monger Lives!", where she remembers Tony's identity as Iron Man and her time as Madame Masque. She returns as Masque to hatch an elaborate scheme in order to ruin Tony's life and kill his friends and family. By the time the episode ends, she seems to be continuing her villainous persona and her vendetta.]]

* The Silver Surver on ''WesternAnimation/TheSuperHeroSquadShow'' was so corrupted by the Infinity Sword, that he turns his back on Galactus and even [[TheStarscream tricks]] Thanos into giving him the complete Infinity Gauntlet. It's rare for a Face Heel Turn to pull a Starscream, but Silver Surfer pulls it off well and becomes the new BigBad till the end of the series.
* Professor Hamilton, a longtime Superman supporter, as seen in ''WesternAnimation/SupermanTheAnimatedSeries'', turns against him in ''[[WesternAnimation/JusticeLeague Justice League Unlimited]]''.

* [[spoiler:Aqualad/Kaldur'ahm]] in Season 2 of ''WesternAnimation/YoungJustice2010'', after he becomes embittered at his former friends for [[spoiler:letting Tula die during a mission gone wrong]] and his own mentor, [[spoiler:Aquaman, for hiding the truth about his real, supervillain father, Black Manta. Kaldur ends up joining him. Later on, it turns out that he only faked his turn and is deep undercover for the team]].